1. Technical Field
The present invention relates to a vehicle occupant seat belt restraint system, and is particularly directed to an energy absorbing device for use in a vehicle occupant seat belt restraint system.
2. Background Art
Many different vehicle occupant seat belt restraint systems are known. A typical vehicle occupant seat belt restraint system includes lap and shoulder belt portions which extend around an occupant seated in a vehicle seat. When the vehicle experiences deceleration such as occurs in a frontal collision, the occupant continues to move in the direction of travel of the vehicle and presses against the lap and shoulder belt portions. If the deceleration is above the locking threshold of the seat belt system, the seat belt locks and the occupant presses against the lap and shoulder belt portions, and the lap and shoulder belt portions are tensioned. In a high energy crash, the tension in the lap and shoulder belt portions may cause excessive loads to be imparted to the occupant. Thus, it can be desirable to (i) allow the occupant to move as the occupant presses against the lap and shoulder belt portions and (ii) dissipate energy transferred into the lap and shoulder belt portions as a function of the occupant's movement.